This invention relates to a space vehicle fuel cell, as well a to a planetary orbital space station or space platform. More particularly, the invention relates to recycling a fuel cell(s) launched into orbit as a modular component(s) for a manned space station. Specifically, the invention is directed to a spacecraft fuel cell configured not only for containing propellants during launch but also for providing a modular structural building component once orbit is achieved for construction of a space station.
Initially, space stations were proposed which were to be completely assembled on the earth and then launched into orbit. Typically, these space stations include interconnected sections capable of being collapsed and stored in the payload compartment of a multistage launch vehicle, launched into planetary orbit, and erected in an operative configuration once orbit is achieved.
Various of these proposed space station configurations comprise inflatable structures collapsible to facilitate launching the structure into space and thereafter erectible to form the space station. One recognized disadvantage of the inflatable space station configuration is that installation of equipment is required after erection of the space station in orbit. A problem encountered by the inflatable space station configuration is damage or destruction caused by micro-meteoroid penetration.
Other configurations for a preformed space
in Berglund, U.S. Pat. No. 3,169,725, and station appear Nesheim, U.S. Pat. No. 3,332,640, which disclose manned space stations including rigid sections collapsible for orbital deployment and thereafter erectible to an operative configuration. Although these space stations constructed of rigid sections allow pre-installation of equipment on the earth and ameliorate the micrometeoroid damage problem, the size and weight of such rigid body space stations is presently limited by the amount of payload that can be launched at one time into orbit by known launch vehicles. One result is that such rigid body space stations are not sufficiently large to allow gravity simulation at low rotational speeds. Also, gas leakage by way of improperly seated gaskets and seals between the mechanically joined sections cannot be corrected without disengaging all of the sections at one time by recollapsing the entire structure.
Berglund, U.S. Pat. No. 3,169,725, and Nesheim, U.S. Pat. No. 3,332,640, allude to launching a number of small units into orbit and assembling them together to form a space station. These patents, however, mention various problems with regard to such a space station configuration, namely, total fuel requirements for deploying numerous units, rendezvous of the various units launched into orbit, and difficulty with actual assembly of the various units in space.
Nevertheless, Hogan, U.S. Pat. No. 4,057,207, and Johnston et al., U.S. Pat. No. 4,122,991, undaunted by the problems mentioned in Berglund, U.S. Pat. No. 3,169,725, and Nesheim, U.S. Pat. No. 3,332,640, disclose space stations constructed from modules or materials launched into space at different times. Hogan, U.S. Pat. No. 4,057,207, discloses a space station constructed from modules adapted to be transported by a space shuttle to a predetermined earth orbit and there joined by a number of other space vehicle modules and all connected together to form a pressure tight space station equipped to support a crew for an extended period of time and large enough to generate simulated gravity at low rotational speeds. Johnston et al., U.S. Pat. No. 4,122,991, discloses an apparatus, referred to as a space spider, for producing a space structure in space from prepunched ribbon or sheet material transported from the earth to the spider at different times by a space shuttle, for example; and, typically, a preformed core is utilized for starting the spinning of the desired space structure. Johnston et al., U.S. Pat. No. 4,122,991, discloses a conical space structure attached to a single expended external tank of a space vehicle, such as used by a space shuttle. Unfortunately, material for construction of the space stations disclosed in Hogan, U.S. Pat. No. 4,057,207, and Johnston et al., U.S. Pat. No. 4,122,991, is transported as payload, such that substantial amounts of fuel are consumed to transport materials to the site of assembly of the space station, which dramatically escalates the cost of construction.
By way of further background, various configurations have been proposed for fuel cells for spacecraft. The space shuttle, for example, is a space transportation vehicle in which space crews use the spacecraft orbiter again and again in launches from the earth. The space shuttle is comprised of an orbiter having main rocket engines, which carries the crew and payload, a large external tank that contains the propellants for the main engines of the orbiter, and two solid rocket boosters. The orbiter and rocket boosters are reusable, but the external tank is currently discarded after each launch. The external tank breaks apart and burns in the upper atmosphere of the earth, and the surviving pieces plunge into the ocean.
The two solid rocket boosters are attached to the external tank so that the thrust from the rocket boosters is transmitted to a cylindrical intertank structure from two forward attaches. The aft attaches of the rocket boosters are hinged to the rear wall of the external tank so as to provide lateral rigidity only and do not transmit the thrust of the solid rocket motors. The fact that the forward oxygen pressure vessel is the heaviest part of the external tank and is cantilevered from the lighter aft hydrogen pressure vessel requires that the thrust of the solid rocket boosters enters at only the forward attaches to the intertank structure. Consequently, the intertank structure must have a high degree of structural integrity and is therefore heavy, because the intertank structure must distribute booster thrust from only two points.
Also, Salkeld, U.S. Pat. No. 3,955,784, and von Pragenau, U.S. Pat. No. 4,452,412, disclose various configurations for propellant tanks on a spacecraft, such as a space shuttle. Salkeld, U.S. Pat. No. 3,955,784, discloses plural on-board propellant tanks incorporated into the body of the spacecraft so that all propellant tanks are reused during subsequent launches. von Pragenau, U.S. Pat. No. 4,452,412, discloses a more typical space shuttle configuration, including an orbiter releasably mounted to an external tank and further including two rocket boosters detachably connected to the external tank. As in the case of the known space shuttle, von Pragenau, U.S. Pat. No. 4,452,412, discloses that the rocket boosters are reused, but that the external tank is jettisoned and breaks apart and burns upon reentry into the atmosphere of the earth over a remote ocean area.